Feeding mechanism for sewing machines



May 3, 1932- R. B. THOMPSON v1,856,360

FEEDING MECHANISM FOR SEWING MACHINES Filed Aug. 6. 1928 2 Sheets-Sheet -l lMay 3,1932. R. B. THOMPSON 1,856,360

FEEDING MECHANISM FOR SEWING MACHINES Filed Aug. 6, 1928 2 Sheets-Sheet 2 Bnvcntor S'QMM f m/ bg Gttornegs Patented May 3, 1932 UNITED STATES PATENT OFFICE uit REUBEN BALL THOMPSON, OF STILLWATER, NEW YORK, ASSIGNOR T WILLCOX & GIBBS SEWING MACHINE COMPANY, OF NEW' YORK, N. Y., Al CORPORATION OF NEW YORK FEEDING MECHANISM FOR SEWING MACHINES Application filed August 6, 1928.

rIhis invention relates to feeding mechanism for sewing machines, and has for its particular object the provision of improved means for adjusting the length of feeding movement or throw of one of the four-motion feed dogs of differential feed mechanisms.

What is now believed to be the preferred embodiment of the invention is illustrated in the accompanying drawings as applied to the well known Overlook sewing machine of the VVillcoX & Gibbs Sewing Machine Company. In said drawings:

Fig. l is a side elevation partly in section;

Fig. 2 is a side elevation of the feeding mechanism detached from the casing and other parts shown in Fig. l;

Fig. 3 is a top view of the parts shown in Fig. 2;

Fig. 4 is an end view looking from the left of Fig. 2;

Fig. 5 is an elevation of the feed rocker detached from the other parts illustrated in connection therewith in Fig. 4;

Fig. 6 is an elevation of the vfeed rocker viewed from the side opposite to that from which Fig. 5 is taken;

Fig. 7 is a horizontal section on line 7-7 of Fig. 4;

f Fig. 8 is an elevation of the rear feed dog and its feed bar and the feed rocker (partly in section) by which said bar is actuated;

Fig. 9 is a similar view of the front feed dog and its feed bar and the feed rocker;

Fig. 10 is a vertical section on lines 10-10 of Figs. 8, 4 and 7, but including` part of the casing which is not shown in said views;

Fig. 11 is a detail view showing the adjusting screw and associated parts;

Figs. l2, 13, 14 and l5 are more detail views of individual parts.

Referring to the parts by reference numerals, 2() is the bed-plate constituting the cover of a box casing parts of which are shown at 2l in Figs. l and l0. 22 is a presserfoot carried by presser-foot bar 23; 24 is a needle carried by a needle bar; 25 is a vertically operating trim-mer blade; 26 is an upstanding deflector, guard or guide-plate; and 27 is a front feed-dog (or feed surface) and 28 is a rear feed dog, both dogs working Serial No. 297,767.

through an opening 29 in the bed plate 2O in engaging and feeding fabric, such as shown at 80, Fig. l. All of these parts are the same as in said commercial Overlook machine.

The feed dogs 27 and 28 are secured to the forward ends of feed bars and 36, respectively, as best shown in Figs. 8 and 9; and each bar is formed with a slideway along its under edge. As shown in Fig. 2 with reference to feed bar 35, a pair of blocks 37 work in said slideway of each bar and an eccentric 38 on shaft 89 works in acircular opening formed between each pair of blocks. By this arrangement rotation of shaft 39 and eccentric 38 thereon imparts up and down movement (of the well known four-motion feed movement) to the feed bars and to the feed dogs carried thereby, all in well-known manner.

A feed rocker, best shown in Figs. 4, 5 and 6, comprises two upstanding parallel arms 40 and 41 connected at their lower ends by a base portion 42, the whole forming a U-shape construction but with the arm 40 shorter than arm 41. The feed rocker fulcrums on stud axles 43 and 44 projecting from opposite ends of the rocker; the stud 44 engaging an opening in the lower end of a bracket arm 45 depending from the under side of bed plate 20, as shown in Fig. l, and the stud 43 engaging an opening in a similar bracket arm not shown.

As shown in Fig. l, rocking movement is imparted to the feed rocker from shaft 89 by means of eccentric 46 on said shaft actuating a bar 47 which is adjustably connected with the feed rocker by means of a pivot stud 48 adjustable in a slot 49 in a vertical liange 50 on the long arm 4l of the feed rocker. The scale of numbers l2, 14, 16, etc., appearing in Figs. l and 2 on the flange 50 along the slot 49, indicates the number of stitches per inch for different positions of adjustment of pivot stud 48.

The rear end of feed bar 86 is connected to the upper end of the short arm 40 of the feed rocker by a pivot pin 55. The feed bar 35, of the front feed dog 27, is supported near its rear end from the feed bar 36 by a shouldered stud screw secured to bar 36 and making sliding engagement in a horizontal slot or guideway 61 in bar 35, whereby vthe bars may move relatively to each other longitudinally. The rear end of feed bar 35 is connected to the feed rocker by a pivotal connect-ion such as to be easily and` accessibly adjustable thereby to vary the length of feeding movement imparted to said feed bar 35 and tothe feed dog 27 carried thereby. At itssaid rear end, feed bar 35 has a downward approximately vertical extension 35a, having therein an upright slot or guideway 62. A feed adjusting slide shoe ,63 (best shown in Figs. 7, 9 and 14) is adjustably movable in said slot 62 and said shoe'63 has an openino engaged byV a pivot stud 64 at one end of a feed adjusting slide 65 which has at its other end a rib or projection 66 making slidingy engagement in an upright groove or guideway 67 in the inner face of arm 41 of the feed rocker-all as shown in Figs. 4, 5 and 13.

A feed adjusting screw 70 engages through an interiorly screw-threaded opening in slide 65, whereby rotation of said screw adjusts .Y the position Vof said slide and thereby moves the pivot stud 64 thereon either closer to the axis (of studs 43 and 44) on which the rocker oscillates-to thereby shorten the feeding movement imparted to feed bar and its feed dog 27, or further from said axis-to thereby lengthen the feeding movement of said bar and its feed dog. At its upper end the screw 70, Fig. 11, has a smooth cylindrical head portion which rotatably engages through an opening 72 in a cap plate 73 (Fig. 12) and has a niclr therein for engagement of ascrew driver. Said cap plate 73 is rigidly secured to the upper end of arm 41 of the feed rocker by means of a screw 7,4 and a rib 75 on the under surface of said cap plate fitting ina groove 76 acrossthe upper end of said arm 41-see particularly Figs. 2, 3, 4,

. 5 and 10. The cap plate 73 thus provides a CII support for the upper end of adjusting'screw 7 0 as well.V as a bearing in which said screw is rotatable.

. At its'lower end screw 7 0 has a smooth cylindrical stem portion 80 of smaller diameter Y extendingrthrough and rotatable in a' sleeve 81, which latterl extends through a vertical opening in the base portion'42 of a feed rocker and is secured therein by a screw 82, the inner end of which engages an opening S33-in said sleeve 81. A head 85, having a roughened peripheral gripping surface, is securedto the lower extremity ofthe stem portion 80 of the adj usting screw bya pin 86 engaging through registeringzopenings in said headV and stem portion-see'Figs 10 and 11. A nick across the end ofV stem portion 80, for engagement by a screw driver, registers with similark nicks across-the head 85.

s will thus readily appear,.to adjust the relativeY to2-that.` of the rear feed dog 28, it

the adjusting screw 7 O and turningthe latter as may be required. By such use of an adjusting screw and associated parts, finely drawn and accurate adjustments, impossible of attainment with feeding mechanisms such as ordinarily providedmay be made'easily and quickly.

What is claimed as newis 1. The combination of a feed rocker having two arms, two feed bars positioned at one end betweenl said arms and pivotally connected at'said end to said arms respectively to beactuated thereby, and an adjusting screw for changing the position of the pivotal connection between one of said arms and its corresponding feed bar relative to the axis of oscillation of said feedroclrer.

2. The combination ofa feed rocker having two arms, two feed bars positioned at one end between saidY arms and pivotally coning two members radiating from the axis of y, oscillation of the rocker, two feed bars positioned at one end side by side between said members of the rocker, a pivot connecting said end of one of said bars to onev of said members of the rocker, an adjustable pivot member connecting said end of the other of said bars to-l the other of said members of the'rocker, said pivot Amember being movable in a gui-deway of said rocker member to- Vwards and from said axis of oscillation of the rocker, and an adjusting screw carried by said rocker andV adapted to change the position of said adjustable pivot member in its said guideway. f Y l in testimony whereof l: have signed this specification. Y

REUBEN BALL THOMPSON.

:feeding movement of the front `feed dog 27 y 

